Mold for forming parts of joints on



June 1942- J; c. JOHNSTON 1 MOLD FOR FORMING PARTS OF JOINTS.ON BELL AND SIEIGOI PIPES Filed May 3, 1937 j inventor @J attorneys Patented June 2, 1942 MOLD FOR FORMING mars or rom'rs N ELL AND srmo'r urns James O. Johnston, Cleveland, Ohio Application May 3, 1937, Serial No. 140,414

3 Claims. (01. 25-428) This invention relates to forming of joints in conduits and the like, and isparticularly applicable to use in sewer pipe and other ceramic, cast iron, or similar pipes which frequently require relatively tight joints between parts which vary somewhat in shape and size.

An object of the invention isto provide an improved means for forming joint sealing material which may be used with conduits and similar ar- Another object is to provide an improved means for forming such materials which may be easily used.

Another object is to provide means for forming joint sealing material which may be readily handled, stored and shipped.

Another object is to provide an improved means for forming such materials which may be readily removed after forming the sealing material.

Another object is to provide an improved means for forming joint sealing material which will be relatively light and compact in construction.

Other objects will hereinafter appear,

The invention will be better understood from the, description of one practical embodiment thereof, illustrated in the accompanying drawing, in which;

Figure 1 is a fragmentary sectional view of two pieces of conduit joined by material formed with the apparatus illustrated in the other figures;

Figure 2 isa fragmentary sectional view of the spigot end of a piece of ceramic conduit associated with a mold and showing a manner in which the sealing material is formed upon this end of the conduit section;

Figure 3 is a similar fragmentary sectional view showing the other mold as it is used in forming sealing material within the belled end of a tile section;

Figure 4 shows the two mold parts in nested relationin a central diametrical cross-section; and

Figure 5 shows the same two parts in perspective.

As is well known, ceramic tiles such as sewer pipes and the like vary considerably in sizeand shape, due both to shrinkage during drying of the clay of which these articles are formed, and through distortion due to expansion and contraction during heating and cooling in the oper- -ation of the firing by which this clay is baked or hardened.

As a result of these changes, the ends of such tile sections vary considerably in dimensions,

an improved sometimes as much as one-quarter inch in diameter, and they often .are slightly out of round. For this reason, it has been found impracticable to make the spigot end of one tile section fit tightly within the belled end of an adjacent section, and for years resort has been had to the expedient of making the interior of the belled end of sections substantially larger than the exterior of the spigot ends, so that an annular space is formed between such ends which may be filled with plastic sealing material.

Various types of mortor, cement and the like have been used for sealing such spaces, as have also asphalt and other bituminous compositions.

While these materials provide an effective seal, some difiiculty has been experienced in their application during the installation of the tile sections, particularly when this must be done in the bottom of the trenches in wet weather, and to overcome this difficulty, I have previously devised a means for applying the sealing material before the sections are installed, this being illustrated. in my prior Patent Number 1,979,470, issued November 6, 1934.

This means was to apply a coating of sealing material to the exterior of the spigot end of the section, and a somewhat similar coating to the interior of the belled end of each section, these coatings being shaped into generally conical formation on their exterior. On installation, the spigot end of one section is wedged into the belled end of an adjacent section and the sealing material caused to 'cohere without having to be poured in a liquid or plastic form.

The present invention comprises a. carrying forward of my prior invention, by providing a simple and convenient means for producing the coatings above referred to, and thus reducing the application of this coating to a simple and easily performed operation. 4

In Figure 1 two pieces of tile conduit are shown, that at the left of the figure, I having a belled end 2 in which is received the spigot end of the section 3. The annular space left between the telescoped. ends of the conduit sections isfilled with a ring 4 of sealing material formed before installation within the belled end 2, and a conjugate ring 5 which has been similarly formed upon the spigot end of section 3.

These two rings of sealing material meet upon a conical surface 6 having a taper which I find is most efliciently about one in twenty. The surfaces of the rings 8 may, if desired, be rendered more plastic and capable of cohesion, as explained in my above mentioned prior patent, by v the use of a solvent or the like.

I find the degree of taper of the conical surfaces to be somewhat critical, as if any less taper than one to twenty be used, it is diflicuit to accurately telescope the rings of sealing material, while if a substantially greater taper is used, they do not become sufficiently tightly wedged together.

In order to form the rings 4 and 5, I have'provided a pair of conjugate molds.

The one for forming the ring upon the spigot end of the tile consists of a disc-like bottom portion I, integral with a peripheral annular wall having its inner surface 9 of frusto-conical shape of substantially the above mentioned taper, one to twenty.

This mold is used as shown in Figure 2 by being placed upon a floor or other supporting surface III, the tile T being set on its spigot end within substantially concentric with the mold and the sealing material ring 5 cast into the annular space between the tile and wall 8. This material is of bituminous composition and is permitted to harden, after which the tile may be readily lifted upwardly and outwardly, the tapered wall 9 of the mold furnishing sufiicient draft to permit easy removal.

A ring of screws I6 is shown, which serves the double purpose of securing the mold to the floor, and being arranged on a circle just slightly-less than the internal diameter of the tile, of helping the user in optically centering the tile in the mold.

The disk-like bottom portion of the mold is further shaped to help the visual centering of the tile therein by being provided with a central hole l1, concentric with the conical surface and only of slightly less diameter than the interior of the tile.

The other mole consists of an annular ring H provided on its exterior with a frusto-conical surface l2, corresponding to surface 9, but which is sufliciently smaller that the two molds may be nested as shown in Figures 4 and 5.

Extending diametrically across the ring II and formed integrally therewith is a bar or handle l3 by which the mold may be conveniently placed in, and removed from, the bell end of the tile.

The lower internal margin of ring I I is formed with a recess or counterbore H, which, as clearly illustrated in Figure 3, lies just above the outwardly flaring part of the belled end of tile T. This space or recess furnishes a bearing for the end of a screw driver or other implement, inserted between the mold and the tile, and which may be used to pry the mold upwardly and loosen it after the ring of sealing material 4 which has been cast about the mold and within the belled end of the tile has hardened.

A slightly smaller counterbored surface I5 formed above recess H, being of substantially the same diameter as the interior of the tile, and

ef'the While I have described the illustrated embodiment of my invention in some particularity, obviously many others will readily occur to those skilled in this art, and I do not, therefore, limit myself to the precise details shown and described, but claim as my invention all embodiments-variations, and modifications thereof coming within the scope of the appended claims.

I claim:

1. A mold for ,use in molding an annular body of sealing material within the bell end of a sectlon of bell-and-spigot pipe, which mold comprises a ring having a frusto-conical exterior surface which with the interior of the bell end of the pipe forms an open topped recess to receive sealing material, the interior of the ring defining a cylindrical surface concentric with the frustoconical surface onits exterior and of substantially the same diameter as the internal diameter of the body of the pipe, whereby the internal surface of the ring may be visually aligned with the internal surface of the pipe, the internal surface of the ring also including a larger diameter surface adjacent the side of the ring which engages the bottom of the bell of the pipe, whereby the ring and pipe form between them a narrow annular space open to the inside of the ring, the ring'having two parallel plane surfaces meeting the frusto-conical surface, and all parts of the mold being positioned between said two plane surfaces, a handle comprising a bar extending diametrically across the ring and integral therewith arranged interiorly of the ring and atits sides spaced therefrom, whereby a tool may be inserted through the interior of the ring into said narrow annular space.

of sealing material at one end of a section of pipe, which mold comprises a ring having a frusto-conical surface which, with the pipe, forms an open topped recess to receive sealing material, the interior of the ring defining a cylindrical space concentric with the frusto-conical surface on the exterior thereof and of substantially the same diameter as the internal diameter of the body of the pipe, whereby the internal surface of the ring may be visually aligned with the internal surface of the body of the pipe,

3. A mold for use in molding an annular body of sealing material within the bell end of a section of bell-and-spigot pipe, which mold comprises a ring having a frusto-conical exterior surface which with the interior of the bell end of the pipe forms an open topped recess to receive sealing material, the interior of the ring defining a cylindrical surface concentric with the frust -conical surface on its exterior and of substan ially the same diameter as the internal diameter of the body of the pipe whereby the internal surface of the ring may be visually aligned with the internal surface of the pipe, the internal surface of the ring also including a larger diameter surface adjacent the side of the ring which engages the bottom of the bell of the pipe whereby the ring and pipe form between them a narrow annular space open to the inside of the ring, the ring having two parallel plane surfaces meeting the frusto-conical surface, and all'parts of the mold being positioned between 'said two plane surfaces. JAMES C. JOHNSTON. 

